I am creating SVG vector images in Affinity Designer (AD). When I import them into Carbide create there is no respecting of size. Both programs are set to measure in milimeters. I must enlarge the imports by a factor of approximately 5.6 to get the proper size. This value is not exact, it varies somewhat making repeatibility an issue. This seems independent of DPI settings.
I did a test export from iDraw, size was spot on. I can copy the AD object, as SVG, paste it into iDraw and export an SVG from there which seems to remedy the issue but at the expense of a bloated work flow with chance for misallignment of components. It also seems a compromise using the less robust iDraw to create.
Any ideas?

There is no actual spec for dpi in svg, it’s just points and vectors. The DPI setting only impacts the bmp preview (which isn’t required) You’re running into that here. The ratio idraw chose matches up with the ratio CC chose, and AD chose a different one. It should however be consistent, which confuses me.

Thank you. I had already tried the bounding rectangle idea.This would certainly help with positioning (0, 0). But the upscaling isn’t always exactly the same value. I’m trying to import multiple “layers”, in quotes because CC doesn’t appear to support them, each of which will be grouped and used for different tool paths on the same substrate, so I need good repeatability.

I kind of poorly edited that in there. The SVG format just plain does not have a “real world measurement” connection to the vectors inside. The DPI affects the preview only, as you say. This isn’t a solvable problem because the format doesn’t do what you want. As Will suggests, if you create a bounding box, you can calculate the scale factor from the presented size when it’s imported. If you don’t want to do any of this, there are other solutions as well. You could do things like do the whole process inside Fusion360, or use inkscape for your vector work and import that into cc.